Has anyone done cool micro-controller projects with their old W123's?
I have an Arduino laying around and would love to integrate it into the car somehow.

Some things I was thinking about:
- Nighttime HUD (since the dash illumination is notoriously dim)
- Back-up distance beeper
- Clock-to-Tachometer conversion (Keeping the hour hand for time but using the
minute hand to display rpm)
- headlight aiming using stepper motors (to actuate the plastic screws on the
headlights to point them around from inside the cab)


Post a reply about your micro-controller projects with your W123!

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I did this Arduino project awhile back - Engine Instrumentation Project

How about a digital CCU?

I’ve been dreaming about gutting a Klima I system and replacing it with an Arduino and toy servos that mimic vacuum pods. Electric monovalve control. Thermistor input. PWM fan control. Micro switch pushbutton controller.

The idea is keep the flaps, evaporator, heater core and blower. That’s it. Everything else to actuate the system will be new.

Design some 3D printed adapters to make vacuum pods using these motors. I think it can be done once and replicated across the car.

OLED temperature and mode display for Def, T/V, Norm and EC + Fan speed.

Two knobs - fan speed and temp.

I think I just hate Klima and I want to start over.

ETA - In other words first replace this:



With this:



I plan on doing this in steps. First adapt the mount and linkage. Then sample the switchover valve voltage (digital input) and pass that on as a pwm output signal to the motor. Once that is designed, replicate it across all flaps using this table as the logic.

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79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles

WOW! This entire thread is really amazing!
WOW! Am I ever old :>(

I hope it works out for you. I had grand Ideas like this but it never materialized. PWM generates rf noise without care and will render your radio unusable.

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1980 N/A 300D with 240d ACC and sanden unit, 281k miles, has a 617.951 turbo motor installed and a 4 speed standard in its future.

I have spent a considerable amount of time thinking about converting the pneumatic climate control system to servos. Further to that, converting the pneumatic locks to electric solenoids with a keyless central locking kit. I'm definitely going to follow this thread and see if I can help out in any way.

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Garage:
1983 300TD
1985 300D
1993 190E 2.6

Social:
Metric Restoration on Instagram

Uh oh. No pressure

Just dreaming right now.

I need to draw up the basic architecture first. There are a bunch of ways put this together. I’m not really settled on a particular way yet.

I think my first step is making a single pod with a controller. If that works that can be replicated for each pod. Then ideally linked together with a central control system that replaces the push button module.

ETA-The locks can be done using existing systems on eBay from China. I have a nice little box that controls four door poppers using a key fob remote. Cost me $14.

__________________
79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles

In entering into the replacement of pneumatic actuators with servo motors, it may be well to keep in mind the forces required. A 2" diameter diaphragm exposed to a 7 psi differential will create a force of 22 lb.

Yikes. I should have said I’m not a mechanical engineer. Huh. That is an issue. I believe this is the force required to overcome that spring in there. It’s pretty strong having rebuilt a few pods. Moving the flaps takes very little force. Wait…but maybe it does take force with the air blowing.

Ok, this is going to take some thought.

__________________
79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles

yk:

As a first step, low force application, consider an actuator for the mono-valve.
Clearly, a proof of concept is well in the past, however, a valve actuator is both a way to initiate application to MB climate controls, and to potentially solve a recurring problem.
The simplest approach is to replicate the MB action: On-Off-On-Off. A more interesting approach is to make the valve positioning continuously variable. Rather than change the ratio of open time to closed time to arrive at the net desired flow, change the position of the valve to yield the desired flow. A stepper motor can do that; a solenoid cannot.

this isn't a micro controller instance, but put a microswitch on the throttle, so at full throttle, it cuts power to the AC compressor clutch so you have maximum power at full throttle.

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1977 240D auto w/OM616.916 engine
2005 Matrix 5spd
2006 Prius

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